Sandbox vectors

Let’s define some vectors which can be used for demonstrations:

manyNumbers <- sample( 1:1000, 20 )
manyNumbers
 [1] 387 958   7 346 620 605 533 138 170 674 367 626 411 833 901  32 788 284 132 168
manyNumbersWithNA <- sample( c( NA, NA, NA, manyNumbers ) )
manyNumbersWithNA
 [1] 533 620 788  NA 901  32 674  NA 958 411 833 605 168 138 284  NA   7 626 132 346 387 170 367
duplicatedNumbers <- sample( 1:5, 10, replace = TRUE )
duplicatedNumbers
 [1] 4 5 3 5 1 5 3 4 4 3
letters
 [1] "a" "b" "c" "d" "e" "f" "g" "h" "i" "j" "k" "l" "m" "n" "o" "p" "q" "r" "s" "t" "u" "v" "w" "x" "y" "z"
LETTERS
 [1] "A" "B" "C" "D" "E" "F" "G" "H" "I" "J" "K" "L" "M" "N" "O" "P" "Q" "R" "S" "T" "U" "V" "W" "X" "Y" "Z"
mixedLetters <- c( sample( letters, 5 ), sample( LETTERS, 5 ) )
mixedLetters
 [1] "e" "m" "p" "u" "z" "P" "O" "X" "W" "N"

Are all/any elements TRUE

all( manyNumbers <= 1000 )
[1] TRUE
all( manyNumbers <= 500 )
[1] FALSE
any( manyNumbers > 1000 )
[1] FALSE
any( manyNumbers > 500 )
[1] TRUE
all( !is.na( manyNumbers ) )
[1] TRUE
any( is.na( manyNumbers ) )
[1] FALSE

Which elements are TRUE

Input: logical vector Output: vector of numbers (positions)

which( manyNumbers > 900 )
[1]  2 15
which( manyNumbersWithNA > 900 )
[1] 5 9
which( is.na( manyNumbersWithNA ) )
[1]  4  8 16

Filtering vector elements

manyNumbers[ manyNumbers > 900 ] # indexing by logical vector
[1] 958 901
manyNumbers[ which( manyNumbers > 900 ) ] # indexing by positions
[1] 958 901
somePositions <- which( manyNumbers > 900 )
manyNumbers[ somePositions ]
[1] 958 901

Are some elements among other elements

"A" %in% LETTERS
[1] TRUE
c( "X", "Y", "Z" ) %in% LETTERS
[1] TRUE TRUE TRUE
all( c( "X", "Y", "Z" ) %in% LETTERS )
[1] TRUE
all( mixedLetters %in% LETTERS )
[1] FALSE
any( mixedLetters %in% LETTERS )
[1] TRUE
mixedLetters[ mixedLetters %in% LETTERS ]
[1] "P" "O" "X" "W" "N"
mixedLetters[ !( mixedLetters %in% LETTERS ) ]
[1] "e" "m" "p" "u" "z"
manyNumbers %in% 300:600
 [1]  TRUE FALSE FALSE  TRUE FALSE FALSE  TRUE FALSE FALSE FALSE  TRUE FALSE  TRUE FALSE FALSE FALSE FALSE
[18] FALSE FALSE FALSE
which( manyNumbers %in% 300:600 )
[1]  1  4  7 11 13
sum( manyNumbers %in% 300:600 )
[1] 5

Pick one of two (three) depending on condition

if_else( manyNumbersWithNA >= 500, "large", "small" )
 [1] "large" "large" "large" NA      "large" "small" "large" NA      "large" "small" "large" "large" "small"
[14] "small" "small" NA      "small" "large" "small" "small" "small" "small" "small"
if_else( manyNumbersWithNA >= 500, "large", "small", "UNKNOWN" )
 [1] "large"   "large"   "large"   "UNKNOWN" "large"   "small"   "large"   "UNKNOWN" "large"   "small"  
[11] "large"   "large"   "small"   "small"   "small"   "UNKNOWN" "small"   "large"   "small"   "small"  
[21] "small"   "small"   "small"  
# here integer 0L is needed instead of real 0.0 
# manyNumbersWithNA contains integer numbers and the method complains
if_else( manyNumbersWithNA >= 500, manyNumbersWithNA, 0L ) 
 [1] 533 620 788  NA 901   0 674  NA 958   0 833 605   0   0   0  NA   0 626   0   0   0   0   0

Duplicates and unique elements

unique( duplicatedNumbers )
[1] 4 5 3 1
unique( c( NA, duplicatedNumbers, NA ) )
[1] NA  4  5  3  1
duplicated( duplicatedNumbers )
 [1] FALSE FALSE FALSE  TRUE FALSE  TRUE  TRUE  TRUE  TRUE  TRUE

Positions of max/min elements

which.max( manyNumbersWithNA )
[1] 9
manyNumbersWithNA[ which.max( manyNumbersWithNA ) ]
[1] 958
which.min( manyNumbersWithNA )
[1] 17
manyNumbersWithNA[ which.min( manyNumbersWithNA ) ]
[1] 7
range( manyNumbersWithNA, na.rm = TRUE )
[1]   7 958

Sorting/ordering of vectors

manyNumbersWithNA
 [1] 533 620 788  NA 901  32 674  NA 958 411 833 605 168 138 284  NA   7 626 132 346 387 170 367
sort( manyNumbersWithNA )
 [1]   7  32 132 138 168 170 284 346 367 387 411 533 605 620 626 674 788 833 901 958
sort( manyNumbersWithNA, na.last = TRUE )
 [1]   7  32 132 138 168 170 284 346 367 387 411 533 605 620 626 674 788 833 901 958  NA  NA  NA
sort( manyNumbersWithNA, na.last = TRUE, decreasing = TRUE )
 [1] 958 901 833 788 674 626 620 605 533 411 387 367 346 284 170 168 138 132  32   7  NA  NA  NA
manyNumbersWithNA[1:5]
[1] 533 620 788  NA 901
order( manyNumbersWithNA[1:5] )
[1] 1 2 3 5 4
rank( manyNumbersWithNA[1:5] )
[1] 1 2 3 5 4
sort( mixedLetters )
 [1] "e" "m" "N" "O" "p" "P" "u" "W" "X" "z"

Ranking of vectors

manyDuplicates <- sample( 10:15, 10, replace = TRUE )
rank( manyDuplicates )
 [1]  1.5  1.5  4.5  4.5  4.5 10.0  4.5  7.5  9.0  7.5
rank( manyDuplicates, ties.method = "min" )
 [1]  1  1  3  3  3 10  3  7  9  7
rank( manyDuplicates, ties.method = "random" )
 [1]  1  2  4  5  6 10  3  7  9  8

Rounding numbers

v <- c( -1, -0.5, 0, 0.5, 1, rnorm( 10 ) )
v
 [1] -1.00000000 -0.50000000  0.00000000  0.50000000  1.00000000  0.03115283  0.57468386 -0.52143619
 [9]  0.07749757  1.22583009 -1.44897350 -0.51782610  0.54115096 -0.45035968 -0.07287477
round( v, 0 )
 [1] -1  0  0  0  1  0  1 -1  0  1 -1 -1  1  0  0
round( v, 1 )
 [1] -1.0 -0.5  0.0  0.5  1.0  0.0  0.6 -0.5  0.1  1.2 -1.4 -0.5  0.5 -0.5 -0.1
round( v, 2 )
 [1] -1.00 -0.50  0.00  0.50  1.00  0.03  0.57 -0.52  0.08  1.23 -1.45 -0.52  0.54 -0.45 -0.07
floor( v )
 [1] -1 -1  0  0  1  0  0 -1  0  1 -2 -1  0 -1 -1
ceiling( v )
 [1] -1  0  0  1  1  1  1  0  1  2 -1  0  1  0  0

Naming vector elements

heights <- c( Amy = 166, Eve = 170, Bob = 177 )
heights
Amy Eve Bob 
166 170 177 
names( heights )
[1] "Amy" "Eve" "Bob"
names( heights ) <- c( "AMY", "EVE", "BOB" )
heights
AMY EVE BOB 
166 170 177 
heights[[ "EVE" ]]
[1] 170

Generating grids

expand_grid( x = c( 1:3, NA ), y = c( "a", "b" ) )
# A tibble: 8 x 2
      x y    
  <int> <chr>
1     1 a    
2     1 b    
3     2 a    
4     2 b    
5     3 a    
6     3 b    
7    NA a    
8    NA b    

Generating combinations

combn( c( "a", "b", "c", "d", "e" ), m = 2, simplify = TRUE )
     [,1] [,2] [,3] [,4] [,5] [,6] [,7] [,8] [,9] [,10]
[1,] "a"  "a"  "a"  "a"  "b"  "b"  "b"  "c"  "c"  "d"  
[2,] "b"  "c"  "d"  "e"  "c"  "d"  "e"  "d"  "e"  "e"  
combn( c( "a", "b", "c", "d", "e" ), m = 3, simplify = TRUE )
     [,1] [,2] [,3] [,4] [,5] [,6] [,7] [,8] [,9] [,10]
[1,] "a"  "a"  "a"  "a"  "a"  "a"  "b"  "b"  "b"  "c"  
[2,] "b"  "b"  "b"  "c"  "c"  "d"  "c"  "c"  "d"  "d"  
[3,] "c"  "d"  "e"  "d"  "e"  "e"  "d"  "e"  "e"  "e"  


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